Required for Apple and Microsoft -compatible HID-over-SPI drivers.
Most logic was already implemented in commit 3c08673438
"spibus: extend API: add cs_delay ivar, KEEP_CS and NO_SLEEP flags".
It dissallowed driver sleeps in the interrupt context. This commit
extends this feature to handle ddb/kdb context with following:
- Skip driver locking if SPI functions were called from kdb/ddb.
- Reinitialize controller if kdb/ddb initiated SPI transfer has
interrupted another already running one. Does not work very
reliable yet.
Reviewed by: manu
Differential Revision: https://reviews.freebsd.org/D41247
Also adds fixups and cleanups:
- apply the child's mode/speed
- implement suspend/resume support
- use RF_SHAREABLE interrupts
- use bus_delayed_attach_children since the transfer can use interrupts
- add support for newly added spibus features (cs_delay and flags)
Operation tested on Broadwell (Wildcat Point) MacBookPro12,1.
Attachment also tested on Kaby Lake (Sunrise Point) Pixelbook.
Reviewed by: wulf
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D29249
Add SPI mode (PIO-only) support for Intel Synchronous Serial Port that
can be found in several Intel's products starting from PXA family.
Most of implementations have slight differences in behavior and in
addresses for registers subset. This driver covers only BayTrail SoC
implementation for it's the only hardware I have to test it on.
Driver attaches to ACPI bus only and does not have PCI or FDT support
for now due to lack of hardware to test it on.
"intelspi" is the best name I've managed to come up with. Linux driver
name (spi-pxa2xx) does not make sense because current implementation
does not support actual PXA2xx SoCs. And as far as I know there is no
codename assigned to Intel SSP chip.
Reviewed by: br, manu
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D8896
